package ooday04;

public class Demo {
    public static void main(String[] args) {


        fu f1=new fu();
        System.out.println();
        f1.hello();
        System.out.println();
        fu f2=new zi();
        System.out.println();
        f2.hello();
        System.out.println();
        zi f3=new zi();
        System.out.println();
        f3.hello();
        System.out.println();
    }
}

class fu{
    fu(){
        this.hello();
        System.out.println("a");}


        public void hello(){
            System.out.println("b");
        }
    }
class zi extends fu{

    zi(){
        System.out.println("c");
    }
    public void hello(){
        super.hello();
        System.out.println("d");
    }
}

